Air suspension with tapered air bag

ABSTRACT

An air bag having a tapered cross-section in the direction of the length of the vehicle has one surface mounted to the vehicle frame. The other surface of the air bag contacts a suspension member which extends outward (as a lever member) from the greater cross-sectional portion of the air bag and the vehicle axle is attached thereto. In one embodiment the suspension member is flexibly coupled to the chassis by flexible cables, or the like, including side cables which prevent side-sway of the vehicle.

United States Patent 1 Gouirand [54] AIR SUSPENSION WITH TAPERED AIR BAG[75] Inventor: Rene Gouirand, New York, N.Y.

[73] Assignee: Joseph Mercadante, Greenwich,

Conn.

22 Filed: Jan.28, 1971 [21] Appl.No 110,704

52 U.S. Cl. ..280/124 F, 293/68 51 Int. Cl ..B6o 11/26 [58] Field ofSearch....280/l24 F; 293/68; 290/1065 [5 6] References Cited UNITEDSTATES PATENTS Benson ..280/l24 F Wedzinga ..280/124 F 1 Jan. 30, 19732,913,252 11/1959 Norrie ..280/124 F 2,882,067 4/1959 Gouirand ..280/124F 2,624,594 1/1953 Gouirand ..280/124 F Primary ExaminerPhilip GoodmanAttorney-F. Eugene Davis, 1V and Robert H. Ware [57] ABSTRACT An air baghaving a tapered cross-section in the direction of the length of thevehicle has one surface mounted to the vehicle frame. The other surfaceof the air bag contacts a suspension member which extends outward (as alever member) from the greater cross-sectional portion of the air bagand the vehicle axle is attached thereto. In one embodiment thesuspension member is flexibly coupled to the chassis by flexible cables,or the like, including side cables which prevent side-sway of thevehicle.

21 Claims, 7 Drawing Figures PATENTEU JAN 3 0 1975 SHEET 10F 3 PATENTEDJAN 3 0 I975 SHEET 2 [IF 3 VQI v PATENTED JAN 3 0 I975 SHEET 3 OF '3 AIRSUSPENSION WITH TAPERED AIR BAG This invention relates to air suspensionsystems for vehicles, and more particularly, for vehicle air suspensionsusing tapered air bags and wherein the load is applied to the air bagsby lever or cantilever action.

The main object of the present invention is to provide improved,reliable, air suspension systems which have a reduced number of movingparts, are simple in construction and are economical to manufacture,require little or no periodic lubrication and provide a smooth vehicleride.

Another object of the present invention is to provide improved airsuspension systems which are suitable for use in both pleasure vehiclesand light and heavy duty trucks or the like.

Yet another object of the present invention is to provide a safetyfeature which includes an air bumper which is in air-communication withthe air suspension system in order to enhance the performance of boththe air bumper and the suspension system.

A further object of the present invention is to provide an embodimenthaving a true floating" action and which is self-aligning, therebyreducing heating up, and the resulting wear, on the tires. Also, fatigueon the metal components of the suspension system is reduced.

SUMMARY OF THE INVENTION According to this invention, a vehiclesuspension system comprises a plate-like chassis member, a platelikesuspension member, an air bag having a tapered cross-section in thedirection of the length of the vehicle and located between the chassismember and the suspension member. Further provided is means coupling avehicle axle to the suspension member such that the substantial portionof the vehicle load is applied at the widest cross-sectional portions ofthe air bag.

According to a further preferred feature of the invention, the vehicleaxle is connected to the suspension member in a cantilever-type mannerand the axle is spaced from the air bag in the direction of the lengthof the vehicle. Using this configuration, by varying the length of thecantilever, the characteristics of the vehicle ride can be varied. Bylengthening the cantilever, the vehicle ride is effectively madesmoother since thev suspension system will allow greater up and downmotions of the axle.

In accordance with a further aspect of this invention, safetyair-bumpers are provided which are in air-communication with the air ina suspension system air bag. The air in the air bumpers acts an anadditional air reservoir for the air bags of the suspension system toeffectively soften the ride of the vehicle and enhance the performanceof the suspension system. Additionally, the air bumper absorbs vehicleimpacts. The air in the suspension system enhances the impact absorptioncharacteristics of the bumper.

DRAWINGS FIG. 1 is a perspective view of an embodiment of the presentinvention for use as the rear suspension for a truck and which providesfloating action;

FIG. 2 is a top view of the embodiment of FIG. 1;

FIG. 3 is a side view of the embodiment of FIG. 1;

FIG. 4 is a top view of an embodiment of the present invention for usein passenger vehicles and in light duty trucks;

FIG. 5 is a side view of the embodiment of FIG. 1;

FIG. 6 is an illustration of typical cables for use in the embodiment ofFIG. 1; and

FIG. 7 illustrates a modified axle construction to facilitate vehicleheight adjustment.

DETAILED DESCRIPTION OF THE DRAWING Referring to FIGS. 1-3, a truckchassis is comprised of longitudinal chassis members 1 and 2 and a crossmember 3. Additional cross members in any suitable configuration can beprovided as required, depending upon the strength desired in thevehicle. The steering, braking and drive mechanism for the vehicle isnot shown so as not to unduly complicate the description. Thesemechanisms, and the interconnection to the vehicle wheels, should beapparent to those ordinarily skilled in the art. The particular designof the chassis members is not relevant to the present invention. The airsuspension can be retrofitted into many existing chassis.

Secured to the frame members 1 and 2 is an upper plate 4 to which issecured an air bag 5, preferably made of rubber or the like, having atapered cross section in the longitudinal direction of the vehicle. Theair bag may be bolted to the plate 4 by means of bolts molded into theair bag 5. One such bolt 6 is shown by way of example in FIG. 3. Theouter periphery in the top view (FIG. 2) of the air bag 5 is round inthe embodiment described. Bearing on the lower end of the air bag 5 is alower plate 7 which is substantially round and conforms generally to theshape of the air bag 5. Plate 7 has an upwardly extending lip portion 8which generally conforms to the cross sectional contour of the air bag 5as most clearly illustrated in FIGS. 1 and 3. Plate 7 is preferablybolted to air bag 5 in the same manner as plate 4 by means of molded inbolts such as bolt 6 ofFIG. 3.

Secured to the lower surface of lower plate 7 are axle support members 9and 10 which retain the axle 11 in position. Support members 9 and 10are secured to lower plate 7 by bolting, welding, or the like andadditionally reinforce and stiffen lower plate 7. Reinforcing members 12and 13 are also secured to lower plate 7 and at their front ends tosupport members 9 and 10, respectively. A cable connecting and furtherreinforcing member 14 is also secured to lower plate 7. Bumper pads 23are provided on chassis members 1 and 2 to absorb shocks if thesuspension system bottoms under extremely severe conditions.

Three cables 15 are provided to flexibly join the front end of lowerplate 7 to upper plate 4. The cables 15 provides a flexible pivot-typepoint for the axle support structure upon impact. Left side cables 16and right side cables 17 are provided to maintain the components intheir relative positions upon impact, during rebound after an impact,and also, prevent side-sway of the vehicle. The side cables also bear onthe air bag 5 upon severe impact and when the bag tends to deform. Thecables provide a flexible component restraining means which is alsocapable of absorbing shock or impact.

Preferably each set of cables 15, 16 and 17 comprise three individualcables as shown in FIGS. l-3. The rearmost side cables are preferablylocated at approximately the center of the air bag 5 as is more clearlyseen in FIG. 3) and the other two side cables in each set are locatedforward thereof. A typical construction of a set of cables is shown indetail in FIG. 6.

Referring to FlG. 6 a set of cables 16, for example, includes threespaced cables 16 embedded in a shield member 18. Shield 18 is to preventrubbing of the air bag by the cables prevents wearing out of the air bagby the action of the cables. Shield 18 may be made of plastic material,rubber, nylon, or any other suitable material. One end of the cableshave eyelets 16a thereon which engage with alternate mating eyelets 4::formed on upper plate 4. When the eyelets 4a and 160 are in matingposition, a bolt 19 is pushed through the eyelets and secured in placewith a nut 20. This flexibly secures cables 16 to plate 4.

The other ends 16b of cables 16 are threaded and pass through holesformed in the reinforcing members of the lower plate 7 or through holesformed in lower plate 7. A nut (not shown) is threaded onto the threadedends 16b of the cables to secure same to the vehicle. The tension on thecables is adjusted by varying the degree of engagement of the nuts withthe cables. If desired, a rubber cushioning bush may be interposedbetween the nuts and the lower plate 7, and/or, rubber bushes can belocated in eyelets 16a to provide additional resiliency.

The axle I] is cantilevered out from the end of the air bag 5.Substantially the whole vehicle load is applied to the largestcross-sectional portions of the tapered air bag 5 as is better seen inFIG. 3. Very little of the load is absorbed at the narrow end of the airbag, that is, the portions closes to cables 15. This type ofconfiguration gives excellent floating suspension action and willprovide a smooth ride. A great deal of flexibility is provided and asway bar is not required. Additionally, since there is no rigidinterconnection between the vehicle axle II and the chassis I, 2, thesuspension is self-aligning for unbalanced loads. This reduces drag onthe wheels and increases tire life. The configuration of FIGS. l-3comprises very few moving parts and requires no periodic lubricationsand no periodic maintenance.

In order to obtain a smoother ride, the leverage could be increased bymoving the axle II farther away from the center of the suspension. Thiswill allow more up and down motions of the wheels and may be preferablein certain instances. Alternatively, by moving the axle ll closer to thecenter of the air bag, the up and down motions of the wheels will bemore restricted and the ride will be less smooth.

In the embodiment of FIGS. l-3, the ride may also be softened by movingthe bolts 6 to a more forward position to allow greater flexing of thelarge cross-sectional portion of the air bag 5 to thereby providegreater freedom of motion.

The configuration of FIGS. l-3, by application of the bulk of the loadto the largest portions of the air bag 5, enables more efficientutilization of space. If the air bag 5 was of uniform cross section, aswould be expected in view of known prior art designs, then the frontportion of the suspension system in the area of cables would necessarilybe made lower to the groundjif the rear portion of the bag is designedfor the maximum loads. This unnecessarily consumes space, increases theweight since more material is used and increases the bulk of the air bagused. By virtue of the tapered air bag, an improved system results.

The air bag 5 may be disc-shaped (as shown) or may be doughnut-shaped.The air bag 5 is connected to an air supply system 21 which isconventional in design. The air supply and bag 5 is also connected to anair bumper 22 which will be described in detail below with reference tothe embodiment of FIGS. 4 and 5. In addition to being a safety feature,the bumper 22 provides an additional air reservoir for bag 5, thusimproving the shock absorption characteristics of the present invention.

Referring to FIGS. 4 and 5, there is shown an embodiment of the presentinvention particularly suitable for use in passenger automobiles or insmall trucks. The illustrated embodiment has independent suspension onall four wheels. However, this is not necessarily required. Thesteering, braking and drive mechanism for the vehicle is not shown so asnot to unduly complicate the description. These mechanisms, and theinterconnection to the vehicle wheels, should be apparent to thoseordinarily skilled in the art.

As shown in FIGS. 4 and 5, all four wheel suspensions are substantiallyidentical. Therefore, only one wheel suspension will be described indetail. One wheel suspension in FIG. 4 is shown in cross-section tofacilitate an understanding of the invention.

A wheel suspension member 30 extends from an axle 31. Member 30 and axle31 may be integrally formed or may be separate members secured together,as described with respect to FIG. 7. Axle 31 is mounted within a tubularmember 32 and a rubber body 33 is located between the shaft 31 andtubular member 32. Rubber body 33 acts as a bearing member and alsoabsorbs some shock. The tubular member 32 is connected to a vehiclechassis member 34 by welding, bolting, or other equivalent manner. Bolts34a are shown merely by way of example. Axle 31 extends through tubularmember 32 and into another tubular member 40 which is also secured tochassis cross member 34 by bolts 34a, for example. Member 40 is commonto two axles as is clearly seen in H6. 4,- the axles being independentof each other. interposed between the axle 31 and tubular member 41 is arubber body 41 which acts as a bearing and absorbs shock.

Rigidly connected to the axle 31 is a suspension member 35 which acts asa lever arm and which is further connected to a circular plate member36. Plate 36 is secured to the upper surface of a tapered air bag 37 bymeans, for example, of bolts 38 molded into the air bag 37. The narrowportion of the air bag 37 is closest to the vehicle axle and the widestportion of the air bag 37 is located remote from the axle 3]. The lowersurface of the air bag 37 is supported by a plate 39 which preferablyforms part of the vehicle chassis. The particular design and shape ofsupport member 39, and its inter-relationship to the chassis, isirrelevant as long as the proper support for the air bag 37 is provided.

In the embodiment of FIGS. 4 and 5, as the vehicle wheel is subjected toshock, the bulk of the applied load on the air bag 37 is applied at thewidest cross-sectional portion thereof. Thus, the air bag 37 iseffectively shaped to absorb shocks in accordance with the intensity ofthe shock applied at the various portions thereof. The load capabilitiesof the air bag is in conformance with the distribution of the appliedload.

The vehicle ride can be made smoother by providing a longer suspensionarm 30. The particular design of the arm 30 is determined by therequirements for the particular vehicle.

The ride can also be made smoother by locating the bolts 38 which securethe air bag to lower chassis members 39 closer to the narrow portions ofthe air bag. This allows more free flexing of the air bag, thussmoothing the vehicle ride. Also the bolts 38 securing the air bag toplate 36 can be placed on a smaller bolt circle to effectively allowmore free flexing of the air bag to provide a smoother vehicle ride.Further, by relocating the bolts 38 the ride characteristics arechanged. By reducing the size of plate 36, the ride is also effectivelymade smoother since more motion of the movable members is permitted. Insummary, the greater the free flexing area of the air bag, the smootherwill be the vehicle ride. All of the above consideration, as well as thematerial from which the air bag is made, should be taken into account invehicle design to provide the desired ride characteristics.

As is clearly seen in FIG. 5, the design of the present inventionefficiently utilizes space. If the air bag were designed with a uniformcross section as would be most probable when using prior art techniques,it would be necessary to locate the arm 35 higher up in the passengerportion of the vehicle. This is because, in order to provide the desiredload carrying capability, the air bag would need a uniform cross-sectioncorresponding to the widest shown in FIG. 5, thus filling the space inthe chassis compartment of FIG. 5. As shown in the present invention,part of arm 35 may be accommodated in the chassis space.

While the embodiment of FIGS. 4 and 5 utilizes fourwheel independentsuspension, and therefore utilizes four air bags one for each wheel theconstruction can be modified so that, for example, both rear wheels arecoupled together on a common shaft and utilize a single air bag. Theoperation of such a rear suspension system is similar to that describedfor the independent wheel suspension and is not described herein. Also,a rear suspension similar to that shown in FIGS. 1-3, scaled down forlighter duty use, may be incorporated into the embodiment of FIGS. 4 and5.

In the embodiments of FIGS. 1-5, improved performance and an additionalsafety feature may be provided by including an air bumper. In such asystem, the air bumper is connected to the air bags of the suspensionsystem either directly or through an intermediate air chamber or supplymeans. A typical bumper is illustrated in FIGS. 4 and 5 and comprises achassis cross member 50 against which an elongated air bag 41 is securedby bolts or the like molded into the air bag. Pivotally secured to thevehicle chassis is an outside bumper plate 52, preferably made of metalor other rigid material which is also bolted or otherwise secured orbonded to air bag 51. The pivot members 53 are shown generally and theparticular design thereof should be apparent. Alternatively, the outsidebumper plate 52 may be maintained in position by means of a cableextending from the upper portion of bumper plate 52 over the top of theair bag 51 and secured to the vehicle chassis plate 50. In this event,it is not necessary to bolt air bag 51 to plates 50 and 52. Preferably,an air line interconnects the air bag 51 with the air suspension system.The air bag 51 will effectively absorb most small external shocksapplied to the vehicle bumper plate 52 and the air contained in the airbag will additionally act as an air reservoir for the suspension systemand as a cushion for improving the softness of the ride of the vehicle.The air bag 51 effectively acts as an additional air reservoir for thesuspension system since they are in air-communication with each other.The air in the suspension system likewise helps absorb shocks applied tothe air bumper. This enhances the ride of the vehicle and providesimproved overall vehicle performance. A similar bumper configuration maybe utilized at the other end of the vehicle. Such an air-bumper issuitable for use in all types of vehicles including trucks, automobile,etc., and even with other types of air or other fluid suspensionsystems.

With the present invention the vehicle road clearance may be easilyadjusted by varying the air pressure. The driver preferably has acontrol coupled to the air supply 21 to enable manual as well asautomatic control of air pressure and thereby, of vehicle roadclearance.

The vehicle road clearance may also be adjusted by varying the positionof suspension arm 30 relative to the axle 31. FIG. 7 illustrates asimplified embodiment for enabling such an adjustment to be easilyeffected.

The end of axle 31 terminates in a generally coneshaped end and the endof the suspension arm 30 remote from the wheel has a mating conicalrecess. Preferably, the conical end and recess have mating grooves orserations to help maintain them in a desired relative position. A bolt31a passes through arm 30 and threadably engages axle 31 to secure thearm 30 and axle 31 together. To adjust vehicle height, the vehicle isjacked up or otherwise lifted, bolt 31a is sufficiently loosened, therelative position of arm 30 with respect to axle 31 is adjusted and thebolt 31a tightened. Then the vehicle is lowered. It should be clear thatother equivalent height adjustment designs may be implemented by thoseskilled in the art.

The air bag shown in the figures is shown merely by way of example. Itshould be clear that various other configurations may be used as thetapered air bag. For example, it is not necessary that the air bag beround as shown in the drawings. The air bag may take an oval or otherdesired peripheral shape. Also, the air bag may take the form of adoughnut shape that is, with a void in the center thereof. The exactshape of the air bag is a matter of design as long as the basicconstructional features of the tapered cross-section in the length ofthe vehicle is maintained.

In the embodiment of FIGS. 1-3, it is preferable that the cables 15secured to the front ends of the plates 4 and 7 are arranged with thecentral cable 15 substantially vertical and the two outer cables 15diverging from the central cable toward the lower ends of the cables.The resulting configuration has the appearance of two inverted V'splaced side by side and having one common leg (the central cable 15being the common leg). By virtue of this arrangement, by varying thedegree of tightness of the two outside cables, the rear wheel suspensioncan be precisely aligned in a relatively simple manner.

The term "air is used in this specification and in the claims forconvenience. It should be clear that any other suitable fluid medium,such as gases or liquids, may be used to practice the concepts of thisinvention disclosed and claim ed in the appended claims.

lclaim:

l. A vehicle suspension system comprising:

a plate-like chassis member;

a plate-like suspension member;

said member forming an acute angle therebetween when the vehicle issubjected to normal loads; an air bag having a tapered cross-section inthe direction of the length of the vehicle located between said chassismember and said suspension member such that the freely flexible area ofthe walls of said air bag between said chassis and said suspensionmember is larger at one end of said air bag than at the other in thedirection of the length of the vehicle; 7

means coupling a vehicle axle to said suspension member such that thesubstantial portion of the vehicle load is applied at the widestcrosssectional portions of said air bag.

2. A suspension system according to claim 1 comprising means forflexibly coupling together said chassis member and said suspensionmember.

3. A suspension system according to claim 2 wherein said flexiblecoupling means couples together said chassis member and said suspensionmember at at least the, narrowest cross-section end of said air bag.

4. A suspension system according to claim 3 wherein said flexiblecoupling means further couples together said chassis member and saidsuspension member at the sides of said air bag.

5. A suspension system according to claim 2 wherein said flexiblecoupling means comprises at least one flexible cable secured to saidmembers and contacting the outer periphery of said air bag. I I

6. A suspension system according to claim 5 wherein said flexiblecoupling means includes a shield interposed between said cables and saidair bag.

7. A suspension system according to claim 4 wherein said flexiblecoupling means comprises a plurality of flexible cable secured to saidmembers and contacting the outer periphery of said air bag.

8. A suspension system according to claim 7 wherein said flexiblecoupling means includes a shield interposed between said cables and saidair bag.

9. A suspension system according to claim 1 wherein said axle is spacedfrom said air bag in the direction of the length ofsaid vehicle.

10. A suspension system according to claim 1 wherein said air bag issecured to said chassis member.

11. A suspension system according to claim 10 wherein said air bag issecured to said suspension member.

12. A suspension system according to claim I wherein said axle couplingmeans includes a lever arm coupled between said axle and said suspensionmember. I

fixed to the vehicle chassis, said axle being rotatably retainedtherein.

17. A suspension system according to claim 12 wherein said chassismember is a lower chassis plate on which is mounted said air bag, andsaid suspension member is a plate bearing against the upper surface ofsaid air bag and coupled to said lever arm.

18. A suspension system according to claim 17 wherein said axle islocated adjacent the narrow crosssectional portion of said air bag andwherein said axle includes a lever extending therefrom, the vehiclewheel being coupled to said lever portion.

19. A vehicle suspension system comprising:

a plate-like chassis member;

a plate-like suspension member;

an air bag having a tapered cross-section in the direction of the lengthof the vehicle located between said chassis member and said suspensionmember; means coupling a vehicle axle to said suspension member suchthat the substantial portion of the vehicle load is applied at thewidest cross-sectional portions of said air bag;

said axle coupling means comprising a lever arm coupled between saidaxle and said suspension member;

said chassis member comprising a lower chassis plate on which is mountedsaid air bag, and said suspension member being a plate bearing againstthe upper surface of said air bag and coupled to said lever arm;

said axle being located adjacent the narrow cross sectional portion ofsaid air bag and said axle comprising a lever extending therefrom, thevehicle wheel being coupled to said lever portion;

said lever portion of said axle being distinct from the main portion ofsaid axle and comprising means adjustable coupling said main and leverportion of said axle together in different relative positions, therebyadjusting vehicle height.

20. A vehicle suspension system comprising:

a plate-like chassis member;

a plate-like suspension member;

an air bag having a tapered cross-section in the direction of the lengthof the vehicle located between said chassis member and said suspensionmember such that the freely flexible area of the walls of said air bagbetween said chassis member and said suspension member is different atthe front and at the rear of said air bag in the direction of the lengthof the vehicle;

means rigidly attaching said air bag to said plate-like chassis memberinwardly of the periphery of said air bag;

coupling means become the sole force transmitting means between saidlever arm and vehicle other than said air bag.

21. A suspension system according to claim 20 and additional freelyflexible high tensile strength coupling means connecting said chassisand said suspension member at opposite sides of said air bag forrestricting downward angular motion of said vehicle axle.

1. A vehicle suspension system comprising: a plate-like chassis member; a plate-like suspension member; said member forming an acute angle therebetween when the vehicle is subjected to normal loads; an air bag having a tapered cross-section in the direction of the length of the vehicle located between said chassis member and said suspension member such that the freely flexible area of the walls of said air bag between said chassis and said suspension member is larger at one end of said air bag than at the other in the direction of the length of the vehicle; means coupling a vehicle axle to said suspension member such that the substantial portion of the vehicle load is applied at the widest cross-sectional portions of said air bag.
 1. A vehicle suspension system comprising: a plate-like chassis member; a plate-like suspension member; said member forming an acute angle therebetween when the vehicle is subjected to normal loads; an air bag having a tapered cross-section in the direction of the length of the vehicle located between said chassis member and said suspension member such that the freely flexible area of the walls of said air bag between said chassis and said suspension member is larger at one end of said air bag than at the other in the direction of the length of the vehicle; means coupling a vehicle axle to said suspension member such that the substantial portion of the vehicle load is applied at the widest cross-sectional portions of said air bag.
 2. A suspension system according to claim 1 comprising means for flexibly coupling together said chassis member and said suspension member.
 3. A suspension system according to claim 2 wherein said flexible coupling means couples together said chassis member and said suspension member at at least the, narrowest cross-section end of said air bag.
 4. A suspension system according to claim 3 wherein said flexible coupling means further couples together said chassis member and said suspension member at the sides of said air bag.
 5. A suspension system according to claim 2 wherein said flexible coupling means comprises at least one flexible cable secured to said members and contacting the outer periphery of said air bag.
 6. A suspension system according to claim 5 wherein said flexible coupling means includes a shield interposed between said cables and said air bag.
 7. A suspension system according to claim 4 wherein said flexible coupling means comprises a plurality of flexible cable secured to said members and contacting the outer periphery of said air bag.
 8. A suspension system according to claim 7 wherein said flexible coupling means includes a shield interposed between said cables and said air bag.
 9. A suspension system according to claim 1 wherein said axle is spaced from said air bag in the direction of the length of said vehicle.
 10. A suspension system according to claim 1 wherein said air bag is secured to said chassis member.
 11. A suspension system according to claim 10 wherein said air bag is secured to said suspension member.
 12. A suspension system according to claim 1 wherein said axle coupling means includes a lever arm coupled beTween said axle and said suspension member.
 13. A suspension system according to claim 12 wherein said axle is spaced from said air bag in the direction of the length of said vehicle.
 14. A suspension system according to claim 12 wherein said lever arm is fixedly connected to said axle.
 15. A suspension system according to claim 14 wherein said axle coupling means includes a bearing member coupled to said vehicle in which said axle is rotatably mounted.
 16. A suspension system according to claim 15 wherein said bearing means includes a tubular member fixed to the vehicle chassis, said axle being rotatably retained therein.
 17. A suspension system according to claim 12 wherein said chassis member is a lower chassis plate on which is mounted said air bag, and said suspension member is a plate bearing against the upper surface of said air bag and coupled to said lever arm.
 18. A suspension system according to claim 17 wherein said axle is located adjacent the narrow cross-sectional portion of said air bag and wherein said axle includes a lever extending therefrom, the vehicle wheel being coupled to said lever portion.
 19. A vehicle suspension system comprising: a plate-like chassis member; a plate-like suspension member; an air bag having a tapered cross-section in the direction of the length of the vehicle located between said chassis member and said suspension member; means coupling a vehicle axle to said suspension member such that the substantial portion of the vehicle load is applied at the widest cross-sectional portions of said air bag; said axle coupling means comprising a lever arm coupled between said axle and said suspension member; said chassis member comprising a lower chassis plate on which is mounted said air bag, and said suspension member being a plate bearing against the upper surface of said air bag and coupled to said lever arm; said axle being located adjacent the narrow cross sectional portion of said air bag and said axle comprising a lever extending therefrom, the vehicle wheel being coupled to said lever portion; said lever portion of said axle being distinct from the main portion of said axle and comprising means adjustable coupling said main and lever portion of said axle together in different relative positions, thereby adjusting vehicle height.
 20. A vehicle suspension system comprising: a plate-like chassis member; a plate-like suspension member; an air bag having a tapered cross-section in the direction of the length of the vehicle located between said chassis member and said suspension member such that the freely flexible area of the walls of said air bag between said chassis member and said suspension member is different at the front and at the rear of said air bag in the direction of the length of the vehicle; means rigidly attaching said air bag to said plate-like chassis member inwardly of the periphery of said air bag; means rigidly attaching said air bag to said plate-like suspension member inwardly of the periphery of said air bag; a lever arm coupling said vehicle axle to said suspension member with the vehicle axle mounted beyond the widest cross-sectional portions of said air bag; freely flexible high tensile strength coupling means connecting the opposite end of said lever arm to said vehicle chassis whereby when loaded said coupling means become the sole force transmitting means between said lever arm and vehicle other than said air bag. 